Radar based target-type vehicle detection

Abstract

A method of identifying target-type vehicle through radar based blind spot warning (BSW) system of a host vehicle, comprising: detecting a first radar reflection point reflected by an object, said first radar reflection point being outside the BSW zone of the BSW system; setting an object area based on the distribution of groups of the first radar reflection point; assuming the object to be other vehicle based on the positional relationship between the object area and the BSW zone; detecting a second radar reflection point inside the BSW zone; and determining the other vehicle to be the target-type vehicle based on the detected second radar reflection point. The target-type vehicle is trailer or coach.

What is claimed is: 
     
       1. A method comprising:
 identifying a target-type vehicle using a radar based blind spot warning (BSW) system of a host vehicle by at least: 
 detecting, with the BSW system, first radar reflection points reflected by an object, said first radar reflection points being outside a BSW zone of the BSW system;
 setting an object area based on a distribution of a group of the first radar reflection points; 
 assuming the object to be another vehicle based on a positional relationship between the object area and the BSW zone; 
 in response to assuming the object to be another vehicle, further determining if there is at least one second radar reflection point detected inside the BSW zone; and 
 determining the another vehicle to be the target-type vehicle based on the detected at least one second radar reflection point. 
 
 
     
     
       2. The method of  claim 1 , wherein determining the another vehicle to be the target-type vehicle comprises determining the another vehicle to be the target-type vehicle when the second radar reflection point is outside the object area. 
     
     
       3. The method of  claim 1 , wherein determining the another vehicle to be the target-type vehicle comprises:
 determining the another vehicle to be the target-type vehicle when the second radar reflection point satisfies a first predetermined condition, 
 said first predetermined condition comprising a distance between the second radar reflection point and the object area being longer than a specific distance, 
 said specific distance is ½ of a length of the object area along a moving direction of the host vehicle, or ½ of a length of the object area along a direction perpendicular to the moving direction of the host vehicle. 
 
     
     
       4. The method of  claim 1 , wherein a height of a bottom surface of the target-type vehicle, between front wheels and rear wheels, is higher than a height of a radar apparatus of the BSW system. 
     
     
       5. The method of  claim 4 , wherein an area of the bottom surface of the target-type vehicle is broader than the BSW zone. 
     
     
       6. The method of  claim 5 , wherein the target-type vehicle comprises a trailer or a coach. 
     
     
       7. The method of  claim 1 , wherein assuming the object to be another vehicle comprises:
 assuming the object to be the another vehicle when the positional relationship between the object area and the BSW zone satisfies a specific positional relationship, 
 said specific positional relationship comprising at least one of a first positional relationship, a second positional relationship, a third positional relationship, a fourth positional relationship, or a fifth positional relationship, wherein
 in the first positional relationship, the object area is behind the BSW zone of the host vehicle, 
 in the second positional relationship, the object area is in front of the BSW zone, 
 in the third positional relationship, the object area is at a side of the BSW zone opposite to the host vehicle, 
 in the fourth positional relationship, the object area is at a side of the BSW zone opposite to the host vehicle and in oblique front of the BSW zone, and 
 in the fifth positional relationship, the object area is at a side of the BSW zone opposite to the host vehicle and in oblique rear of the BSW zone. 
 
 
     
     
       8. The method of  claim 7 , wherein said specific positional relationship satisfies at least two of the first through fifth positional relationships. 
     
     
       9. The method of  claim 7 , wherein said specific positional relationship is based on a prerequisite that the first positional relationship is satisfied, and that either of the third and fifth positional relationships is satisfied. 
     
     
       10. The method of  claim 1 , wherein assuming the object to be the another vehicle comprises:
 assuming the object to be the another vehicle based on a relative speed of the first radar reflection points with respect to the host vehicle. 
 
     
     
       11. The method of  claim 1 , wherein determining if there is at least one second radar reflection point detected inside the BSW zone comprises:
 determining, among the one or more reflection points detected inside the BSW zone, a specific interference point satisfying a second predetermined condition, said second predetermined condition comprise at least one of: an electromagnetic wave intensity of a reflection wave from the second radar reflection point is less than a first threshold, a distance alteration rate of the reflection wave from the second radar reflection point is substantially zero, or an angle accuracy index of reflection waves from second radar reflection point is the worst; and 
 excluding the specific interference point from the second radar reflection point. 
 
     
     
       12. The method of  claim 10 , wherein detecting the second radar reflection point comprises determining a reflection point corresponding to a reflected wave intermittently detected. 
     
     
       13. The method of  claim 1 , wherein detecting the second radar reflection point comprises: determining the second radar reflection point having characteristics of radar reflection wave reflected by a bottom surface of a vehicle chassis higher than a mounting height of radar of the host vehicle. 
     
     
       14. The method of  claim 1 , further comprising outputting a notification of the another vehicle being of the target-type vehicle identified. 
     
     
       15. The method of  claim 1 , wherein the second radar reflection point is reflected by at least one of the another vehicle and a trailer pulled by the another vehicle. 
     
     
       16. The method of  claim 15 , wherein:
 the first radar reflection points are associated with a first portion of the at least one the another vehicle and the trailer; and 
 the second radar reflection point is associated with a second portion of the at least one of the another vehicle and the trailer. 
 
     
     
       17. A driving assistance system, comprising:
 a radar based blind spot warning (BSW) system mounted on a vehicle, said system comprising a processing unit configured to:
 detect first radar reflection points reflected by an object, said first radar reflection points being outside a BSW zone of the BSW system; 
 set an object area based on a distribution of a group of the first radar reflection points; 
 deduce the object to be another vehicle based on a positional relationship between the object area and the BSW zone; 
 in response to deducing the object to be another vehicle, further determining if there is at least one second radar reflection point detected inside the BSW zone; and 
 determine the another vehicle to be target-type vehicle based on the detected at least one second radar reflection point; and 
 
 a driving assistance ECU configured to:
 receive a signal from the BSW system; and 
 based on said signal, output information to notify a driver that the object is the target-type vehicle. 
 
 
     
     
       18. The driving assistance system of  claim 17 , wherein the BSW system is configured to determine the another vehicle to be the target-type vehicle by determining the another vehicle to be the target-type vehicle when the second radar reflection point is outside the object area. 
     
     
       19. A computer-readable media comprising instructions that, when executed, configure a blind spot warning system (BSW) of a host vehicle to identify a target-type vehicle by:
 detecting first radar reflection points reflected by an object, said first radar reflection points being outside a BSW zone of the BSW system; 
 setting an object area based on a distribution of a group of the first radar reflection points; 
 assuming the object to be another vehicle based on a positional relationship between the object area and the BSW zone; 
 in response to assuming the object to be another vehicle, further determining if there is at least one second radar reflection point detected inside the BSW zone; and 
 determining the another vehicle to be the target-type vehicle based on the detected at least one second radar reflection point. 
 
     
     
       20. The computer-readable media of  claim 19 , wherein the instructions, when executed, configure the BSW to determine the another vehicle to be the target-type vehicle by determining the another vehicle to be the target-type vehicle when the second radar reflection point is outside the object area. 
     
     
       21. The computer-readable media of  claim 19 , wherein a height of a bottom surface of the target-type vehicle, between front wheels and rear wheels, is higher than a height of a radar apparatus of the BSW system. 
     
     
       22. The computer-readable media of  claim 20 , wherein an area of a bottom surface of the target-type vehicle is broader than the BSW zone.